Modeling an engineering design application using extended object-oriented concepts

Abstract

This paper presents an approach to extend object-oriented data models, in which versions of an object are allowed to appear at different levels of an inheritance hierarchy, in contrast to the known approaches where they are admitted only at one leveI. This approach allows the design and instantiation of objects to beco me very natural, starting with the design of an object in a class and refining it, adding properties to the subclasses. Versions of objects can be defined in a subclass, having ascendant versions/objects associated to the superclasses. The paper also discusses how the extended model can be used to model engineering applications, fulfilling their requirements. The application is the STAR frarnework, which implements an innovative and flexible data model that allows the user to define an object schema for each design object. Design alternatives and views can be created during the design process and are represented in the object schema. Versioning appears in the STAR model not only for the real design data, but also for alternatives and views in the object schema. This requirement is not naturally modeled by the existing version models in object-oriented databases.